I have the exact same issues.
Certain days, I'll wake up with a very "active" libido. Anything will turn me on. Every other day is the emotional storm that you describe, with a complete absence of libido. Erections are possible, but forced. I
do not ever get "morning wood." I
never have spontaneous erections. Also, I have
never had a wet dream in my 27 years.
Tell me, are you still able to masturbate when you are having one of your no-libido days? In my experience, it is physically possible, but strenuous, and there is absolutely none of the chemical release that accompanys a normal orgasm.
Normally, I'll have an unexplanable libido for one week. It tapers off towards the end. Then, I'll have 4 or 5 weeks without any libido at all. Honestly, it makes being male, or even human, downright confusing. To compound your issue, my "swings" started at age 14 and were usually 48 hour peroids. One day "on," one day "off." As I got older, that time began to increase. I have had low
testosterone for my entire life, so perhaps that is why I've had so much experience with this.
What is your SHBG level? How about
DHT?